Actually if you look for studies about violence and video games. Most studies find that the people who have any kind of violent behavior do one of the following. Play extremely violent games for more than like 8 hours a day. Or these kids play none at all.

If you remember a while back there was a shooting at uhhh Virginia.. in some college. Anyway when they asked that guys roommates if he played any video games, they said that he didn't.

Point being do some research you will find that most studies conclusively say that video games do not cause violent behavior.